KR100994091B1 - Paper improver - Google Patents

Abstract

Provided is a paper making agent for papermaking, which can improve the volume, whiteness, and opacity of a sheet obtained by papermaking a pulp material even under high speed papermaking conditions, and can improve paper force. Copolymer (A) which has a structural unit derived from 1 or more types of nonionic monomers whose melting parameter is 20.5 (MPa) ^1/2 or less, and a structural unit derived from 1 or more types of anionic or cationic monomers, and an interface The active agent (B) is contained in a specific weight ratio, and (i) the standard volumetric enhancement is at least 0.02 g / cm 3, (ii) the standard opacity enhancement is at least 1.0 point, and (iii) the standard whiteness enhancement is at least 0.5 point. It is a papermaking paper improver that produces one or more paper quality enhancing effects.

Paper Quality Enhancer

Description

Paper Enhancer {PAPER IMPROVER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper quality improver for paper making, which can improve optical properties such as volume, whiteness or opacity of a sheet obtained by papermaking a pulp material, and also improve paper force.

From the standpoint of protecting the environment, it is desired to reduce the amount of pulp used, and as a result, it is desired to reduce the weight of paper and to increase and increase paper pulp. However, the paper obtained by simply reducing the amount of pulp in the paper has a decrease in opacity as the paper becomes thinner, resulting in poor quality. In addition, in the case of weight reduction in which the amount of pulp in the paper is reduced, the paper is required to have strength proportional to the square of the thickness, such as cardboard, which is not preferable. On the other hand, when the blending ratio of the used paper pulp is increased, the paper thickness decreases due to the decrease in the whiteness due to residual ink in the used paper pulp, or the thinning of the pulp itself in the recycling process, resulting in a decrease in opacity. Therefore, when the amount of pulp in the paper is reduced and the blending ratio of the used paper pulp is increased, the opacity and whiteness of the paper obtained are further reduced. In addition, when the white paper is increased by deinking or bleaching the paper pulp that causes a decrease in the whiteness, the opacity of the paper obtained is further reduced, which is undesirable.                 

In order to prevent the fall of the thickness due to weight reduction, various volume improvement methods have been tried in the past. For example, the manufacturing method which makes a press pressure low has the problem that smoothness falls and printability falls. In addition, a method of using crosslinked pulp, mixing with synthetic fibers, filling fillers such as inorganic materials between the pulp fibers, or bringing voids may be used, but recycling of the pulp may be impossible or the smoothness of paper may be impaired. . In addition, Japanese Patent No. 2971447 is known as a volume improver for paper, but there is a problem that the paper force performance is insufficient.

In addition, additives for papermaking which can achieve a whiteness improvement, an opacity improvement, and a volume improvement effect of paper, and are superior in paper force improvement performance to conventional paper volume improvers (Japanese Patent Laid-Open No. 2002-115199, Japanese Patent Laid-Open No. 2001) -248100).

There is a need in the art for paper quality improvers having higher volumetric performance in high shear conditions at high papermaking speed. High-speed papermaking is not like papermaking as described in the prior art, but pulp is diluted with a large amount of water, and papermaking is carried out in a static condition in which filtration is carried out by its own weight. It is a papermaking method in the dynamic conditions by which a pulp slurry is sprayed continuously to the surface which a wire is moving, and a high shear force is applied, and it can carry out laboratoryly using an orientation paper machine etc.

On the other hand, in order to improve opacity and whiteness, the method of adding a large amount (for example, 5-20 weight%) of inorganic materials, such as calcium carbonate, kaolin, and white carbon, is performed in the art. However, simply adding a large amount of inorganic filler is remarkable in weight increase of the paper. For example, even if the pulp amount is reduced and the inorganic filler is added, the weight reduction of the paper cannot be achieved. In particular, when the inorganic filler is added to the used paper pulp, a large amount is required, and weight reduction of the paper becomes more difficult.

Disclosure of Invention

The present invention can achieve at least one of improving the whiteness, opacity, and volume of the paper by adding it to any one of the processes before the papermaking process under high-speed papermaking conditions. It is an object to provide an excellent papermaking improver for papermaking.

The present invention is a copolymer (A) having a structural unit derived from one or more kinds of nonionic monomers having a dissolution parameter of 20.5 (MPa) ^1/2 or less and a structural unit derived from one or more kinds of anionic or cationic monomers. And surfactant (B) in the range of (A) / (B) = 99/1 to 1/99 (weight ratio), and further improving the paper quality of at least one of the following (i), (ii) and (iii) It is a paper quality improver that produces effects.

(i) a standard volume improvement of at least 0.02 g / cm 3

(ii) a standard opacity improvement of at least 1.0 point

(iii) a standard whiteness improvement of at least 0.5 point

The present invention provides a copolymer having a structural unit derived from at least one of a nonionic unsaturated monomer having a dissolution parameter of 20.5 (MPa) ^1/2 or less and a structural unit derived from at least one of anionic or cationic monomers ( A) and surfactant (B) in the range of (A) / (B) = 99/1/99 (weight ratio), and also at least one of the following (i), (ii), (iii) It is a paper quality improver for papermaking that has an effect of improving paper quality.

(i) a standard volume improvement of at least 0.02 g / cm 3

(ii) a standard opacity improvement of at least 1.0 point

(iii) a standard whiteness improvement of at least 0.5 point

The present invention is derived from one or more of anionic or cationic monomers in 5 to 84% by weight in total of the structural units derived from one or more types of nonionic monomers having a dissolution parameter of 20.5 (MPa) ^1/2 or less. The second containing the copolymer (A) which has a structural unit in 1 to 80 weight% in a polymer total, and surfactant (B) in the range of (A) / (B) = 99 / 1-1 / 99 (weight ratio). It is a paper quality improver.

The measuring method of standard volume improvement, standard whiteness improvement, and standard opacity improvement in this invention is described in detail.

<Measurement Method of Standard Volume Enhancement>

① After cutting beech-derived hardwood bleached kraft pulp (hereinafter referred to as LBKP) to 5 cm × 5 cm, it is understood that a certain amount as a beater at 25 ± 3 ℃ and the standard Canadian filtered water (JIS P 8121) Beating to 410 ± 20 ml to obtain an LBKP slurry with a pulp concentration of 0.4% by weight.

The pulp slurry was weighed so that the sheet basis weight after humidity was 84 +/- 2 g / m <2>, and it contained the copolymer (A) and surfactant (B) in the range of 1 / 99-99 / 1 (weight ratio). 2.0 weight part of paper quality improvers are added with respect to 100 weight part of pulp, and it is made of 80 mesh wire using the experimental orientation paper machine (made by Kumagai-Riki Industrial Co., Ltd.) on the following conditions, and a wet sheet is obtained.

[Papermaking condition]

Grassland Speed: 800m / min

Injection pressure: 0.1 MPa

Spray nozzle: small

Injection nozzle angle: 85 °

Injection nozzle distance: 40 mm

Dewatering Speed: 500r / min

Dehydration time: 30 seconds.

The obtained wet sheet was divided into three parts, and each was produced by Advantech Orient Co., Ltd. filter paper No. 26 (270 mm x 270 mm) Two coaches and a coach plate are piled up and coached. With each of the two new filter papers, press the top and bottom of the sheet for 5 minutes at a clamping pressure of 340 ± 10 kPa. After pressing, only the sheet is dried for 2 minutes at 105 ± 3 ° C. using a mirror dryer. The dried sheet is moistened for at least 5 hours at 23 ° C. and 50% humidity. The moistened sheet is cut to 150 x 150 mm.

(2) Measure the weight of the cut sheet and find the basis weight (g / m 2) by the following formula (3).                 

Basis weight (g / ㎡) = sheet weight / 0.0225 (3)

Next, the thickness of the humidified sheet | seat is measured at 5 places or more by the pressure of 53.9 +/- 4.9 kPa using the micrometer for paper, and makes the average value obtained as thickness (mm).

(3) From the basis weight and thickness obtained above, density d (g / cm <3>) is calculated | required by following formula (4).

d = basis weight / thickness / 1000 (4)

Further, the preparation in the same manner without adding the papermaking sheet jongyijil improved compounds in question, and the density determined in the same manner as d _0.

④ obtained a density d,, the volume increase by the following formula (5) from d ₀ is also calculated in the above.

Standard Volume Enhancement (g / cm 3) = d ₀ -d (5).

<Measurement Method of Standard Whiteness Enhancement>

① Same as ① in the standard volumetric measurement method.

(2) The humidified sheet measures whiteness B according to JIS P 8123 Hunter whiteness. Further, in the same manner without adding the papermaking jongyijil enhancing agent to prepare a sheet, and the degree of whiteness obtained in the same manner as B _0.

It ③ obtain a standard whiteness improvement also by the following formula (6) from the brightness B, B ₀ obtained above. Standard Whiteness Enhancement (Point) = B-B ₀ (6).

<Measurement Method of Standard Opacity Enhancement>

① Same as ① of standard volumetric measurement method.

(2) The wetted sheet measures the opacity P in accordance with JIS P 8138A. Further, the preparation in the same manner without adding the papermaking sheet jongyijil improving agent, and opacity obtained in the same manner as P _0.

(3) calculate the opacity P,, improved standard opacity by the following formula (7) from P ₀ is also calculated in the above.

Standard opacity improvement (point) = P-P ₀ (7).

Moreover, it is preferable that the paper-quality paper improvement agent for papermaking by this invention brings about the effect of the standard non-rupture strength improvement index -3000 or more defined by this specification. Usually, when the density of paper is reduced by the same basis weight and the volume is improved, the non-rupture strength is lowered. The standard non-rupture strength improvement index is an index indicating how much the non-rupture strength is maintained when the volume is increased under the measurement conditions of the standard volume improvement. If the value is positive, the non-rupture strength is improved. If the value is negative, the non-rupture strength is decreased. However, in the present invention, if the standard non-rupture strength improvement index is -3000 or more, the volume improvement and the ratio It is preferable from the viewpoint of maintaining the burst strength. The measurement method of the standard non-rupture strength improvement index is as follows.

<Measurement method of standard non-rupture strength improvement index>                 

① Same as ① of standard volumetric measurement method.

(2) The humidified sheet measures specific burst strength s in accordance with JIS P 8112. In addition, a sheet is similarly prepared without adding the papermaking paper improver, and the non-rupture strength obtained by the same method is set to S ₀ . In addition, the standard volumetric improvement is measured by the above method for each sheet.

(4) If the standard volumetric improvement is 0g / cm3 or less, the standard non-rupture strength improvement index is undefined. In addition, when standard volume improvement exceeds 0g / cm <3>, a standard non-rupture intensity improvement index is calculated | required by following formula (8).

Standard non-rupture strength improvement index = (s / S ₀ × 100-100) / standard volume improvement (8).

Thus, by measuring the paper volume improver containing a specific copolymer and surfactant, standard volume improvement, standard white improvement, standard opacity improvement, and also standard non-rupture strength improvement index by a predetermined method, Paper enhancers are readily specified.

Moreover, this invention relates to the manufacturing method of the pulp sheet which adds the papermaking paper improvement agent of the said invention in any one process before a papermaking process, and is also annealing at papermaking speed of 200 m / min or more. The present invention also relates to a pulp sheet containing the papermaking improving agent for papermaking of the present invention.

The mechanism of expression of the effects of the present invention is not clear, but is estimated as follows. When the copolymer (A) according to the present invention is added to the pulp slurry, the anion or cationic portion of the charged copolymer (A) is adsorbed onto the pulp fiber, and the dissolution parameter is 20.5 (MPa) ^1/2 or less and is nonionic. Since the structure derived from a monomer shows hydrophobicity, the hydrophobic part comes out to the surface and hydrophobizes the pulp surface. As a result, the interfacial tension between the pulp and the aqueous solution is increased, the gap is increased between the pulp at the time of papermaking, a bulky pulp sheet is obtained, or the optical reflectivity is increased, thereby improving the opacity and the whiteness. However, in a situation where the papermaking speed is high and a high shear force is applied, the adsorption state of the copolymer (A) to the pulp becomes uneven, and the pulp surface cannot be sufficiently hydrophobized, and the volume improvement becomes small. The surfactant (B) acts on the copolymer (A) at this time, so that the adsorption form on the pulp surface of the copolymer (A) is efficiently maintained even under high shear conditions, and as a result, the pulp surface is considered to be hydrophobized efficiently. . Moreover, since copolymer (A) is disperse | distributed uniformly on the pulp surface and adsorb | sucking in a refined state, it is thought that paper force improves.

On the other hand, even if the gap between the pulp increases, the structure in which the copolymer is derived from a monomer having a dissolution parameter of 26.6 (MPa) ^1/2 or more is hydrophilic, and since the portion having high hydrophilicity interacts with the pulp and hydrogen bond interaction, Maintained, paper force is further enhanced. When the crosslinkable monomer is introduced, it is considered that the molecular weight of the copolymer is increased and the molecular size is also increased, thereby facilitating the bonding between the pulp and the enhancement effect of the paper force.

The copolymer (A) used for this invention is a structural unit derived from the structural unit derived from 1 or more types of nonionic monomers whose dissolution parameter is 20.5 (MPa) ^1/2 or less, and the structural unit derived from 1 or more types of anionic or cationic monomers. As what has, for example, a vinyl polymer, polyester, a polysaccharide derivative, etc. are mentioned. Preferably it has a structural unit derived from 1 or more types of nonionic unsaturated monomers whose dissolution parameter is 20.5 (MPa) ^1/2 or less, and the structural unit derived from 1 or more types of anionic or cationic monomers, for example, Vinyl polymers; and the like.

As the dissolution parameter (δ) referred to herein, the value described in P0LYMER HANDB0OK (J. Brandrup and E. H. Immergut, third edition) is used. If the structure is not described directly, the value calculated by the method described in VII / 519 of that document is used. In other words,

δ = ((H-R × 298.15) / V) ^1/2 (unit: (㎈ / ㎥) ^1/2 or × 2.046 (MPa) ^1/2 )

H: evaporation enthalpy [unit: (㎈ / mol) or (× 4.186 J / mol)]

R: gas constant [unit: (1.98719 kV / Kmol) or (1.98719 x 4.186 J / Kmol)]

V: mol volume (cm 3 / mol)

The value calculated by In the present specification, H is                 

H = -2950 + 23.7 T _b + 0.020 T _b ² [unit: (㎈ / mol) or (× 4.186 J / mol)]

T _b : Standard boiling point [unit: K]

The empirically expressed value was used to obtain a standard boiling point (T _b ). The standard boiling point (T _b ) of the monomer uses the values described in the Aldrich (2000-2001: JAPAN) reagent catalog and, if the boiling point is described under reduced pressure, the boiling point at atmospheric pressure from the pressure-temperature calculation table in the table attached to this booklet. Was obtained. In addition, regarding the monomer which is not described in this booklet, and the monomer which does not have a boiling point, the dissolution parameter (delta) in 25 degreeC was calculated | required by the following formula using the Group Contribution method.

δ = ΣF _i / V

F: molar suction constant [unit: (mm 3 / mol) ^1/2 cm 3 / mol or x 2.046 (MPa) ^1/2 cm 3 / mol)

In addition, in this specification, F was calculated | required using the value of Hoy. Below, the calculation example of the dissolution parameter (delta) of a monomer is shown.

[Calculation example 1]

Monomer: Acrylamide (Molecular weight: 71.08, T _b : 235 ° C., Specific gravity: 1.12)

H = -2950 + 23.7 × 508.15 + 0.020 × (508.15) ² = 14257.9

V = 71.08 / 1.12 = 63.4                 

δ = ((H-1.98719 × 298.15) / V) ^1/2 = 14.7 (m 3 / m 3) ^1/2 = 30.1 (MPa) ^1/2 .

[Calculation example 2]

Monomer: tertiary octylacrylamide (molecular weight: 183.3, specific gravity: 0.86)

Number F (unit: (mm 3 / mol) ^1/2 cm 3 / mol or x 2.046 (MPa) ^1/2 cm 3 / mol)

-CH ₃ 5 148.3

-CH _2-1 131.5

＞ CH-1 85.99

＞ C <2 32.03

H ₂ C = 1 126.54

-CO- 1 262.96

-NH- 1 180.03

Basic Value 135.1

δ = (148.3 × 5 + 131.5 + 85.99 + 32.03 × 2 + 126.54 + 262.96 + 180.03 + 135.1) / (183.3 / 0.86) = 8.1 (㎈ / ㎥) ^1/2 = 16.6 (MPa) ^1/2 .

The nonionic monomer mentioned in this specification is a monomer which is not anionic or cationic by a change of pH. In addition, the anionic or cationic monomer mentioned in this specification is not only the monomer which always shows anionic or cationic, but also the monomer which may become ionic by the change of pH.

Saturation or unsaturated may be sufficient as the nonionic monomer whose melt | dissolution parameter which comprises the copolymer (A) of this invention is 20.5 or less [a unit (MPa) ^1/2 is omitted hereafter] or less. Especially unsaturated monomer is preferable, For example, C1-C40 of (meth) acrylic acid, Preferably C2-C24 alkyl ester, C1-C40 of vinyl alcohol, Preferably C2-C24 alkyl acid ester, Carbon number Alkyl modified (meth) acrylamide having 2 to 40, preferably carbon atoms having 3 to 24 carbon atoms, alkoxy modified (meth) acrylamide having 2 to 40 carbon atoms, preferably having 3 to 24 carbon atoms, having 1 to 40 carbon atoms of maleic acid or Dialkyl esters, C1-40 mono or dialkyl esters of fumaric acid, styrene, vinyltoluene, α-methylstyrene, ethylene, propylene, butadiene, polyalkylene glycol (meth) acrylates, alkoxypolyalkylene glycols (meth) Acrylate, polyalkylene glycol alkenyl ether, alkoxy polyalkylene glycol alkenyl ether, etc. are mentioned.

As an anionic monomer which comprises the copolymer (A) of this invention, an unsaturated monomer is preferable, For example, Monocarboxylic acids, such as (meth) acrylic acid and crotonic acid; Dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and muconic acid, or half esters thereof; Sodium salts, potassium salts, ammonium salts and the like, such as organic sulfonic acids such as vinylsulfonic acid, styrenesulfonic acid and 2-acrylamide-2-methylpropanesulfonic acid are used.

As a cationic monomer which comprises the copolymer (A) of this invention, an unsaturated monomer is preferable, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, Diethylaminopropyl (meth) acrylamide, allylamine, diallylamine, triallylamine; Or inorganic acids such as hydrochloric acid, sulfuric acid, acetic acid, phosphoric acid, salts of organic acids, or methyl halides (chloride, bromide, etc.), ethyl halides (chloride, bromide, etc.), benzyl halides (chloride, bromide, etc.), dialkyl (methyl And vinyl monomers containing a quaternary ammonium salt obtained by reaction with a quaternizing agent such as sulfuric acid, dialkyl (methyl, ethyl and the like) carbonic acid, epichlorohydrin and the like. Moreover, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, allylamine, diallylamine, triallylamine After copolymerizing silver, it can be used by treating with salts of inorganic acids, such as hydrochloric acid, a sulfuric acid, an acetic acid, phosphoric acid, and an organic acid.

The copolymer (A) of the present invention may also have a structural unit having a dissolution parameter of 26.6 or more and derived from one or more types of nonionic unsaturated monomers. Acrylamide is mentioned especially as a nonionic unsaturated monomer whose dissolution parameter is 26.6 or more.

In addition, a crosslinkable monomer can be used in part for the unsaturated monomer which comprises a copolymer (A) from a viewpoint of paper force improvement. The crosslinkable monomer may be a nonionic unsaturated monomer having an above-described dissolution parameter of 20.5 or less, an anionic monomer, a cationic monomer, a nonionic unsaturated monomer having a dissolution parameter of 26.6 or more, or a monomer which does not belong to these. Since the degree of crosslinking depends largely on the molar ratio, the ratio is preferably 0.001 to 5 mol%, more preferably 0.01 to 1 mol%, particularly preferably 0.05 to 0.5 mol% based on the total constituent monomers. As a crosslinkable monomer, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, hexamethylenebis (meth) acrylamide, ethylene glycol di (meth) acrylate, diethylene glycol di (meth), for example ) Bifunctional crosslinkable monomers such as acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, divinylbenzene, and diallyl (meth) acrylamide, or 1,3,5- Polyfunctional crosslinkable monomers such as triacryloyl hexahydro-S-triazine, triallyl isocyanurate, pentaerythritol triacrylate, trimethylolpropane acrylate, triacyl formal, diacryloimide and the like Used.

As for the monomer composition ratio of the copolymer (A) which concerns on this invention, from the viewpoint of volume improvement, opacity, whiteness improvement, and paper force improvement, 5-84 weight% is preferable for the nonionic monomer whose dissolution parameter is 20.5 or less, 10 70 weight% is more preferable, 15-60 weight% is especially preferable, and 20-50 weight% is more preferable. The anionic monomer and / or the cationic monomer is preferably 1 to 80% by weight in total, more preferably 3 to 50% by weight, particularly preferably 5 to 30% by weight, and a dissolution parameter of 26.6 or more. 15-94 weight% is preferable, 20-80 weight% is more preferable, 40-70 weight% is especially preferable. In addition, this composition ratio may be the thing at the time of monomer input.

The ratio of the constituent monomer of the copolymer (A) is 5 to 84% by weight of the nonionic monomer having a dissolution parameter of 20.5 or less, 1 to 80% by weight in total of the anionic monomer and the cationic monomer, and a nonionic unsaturated having a dissolution parameter of 26.6 or more. A combination of 15 to 94% by weight of monomers is preferred.

In addition, the copolymer according to the present invention preferably has a weight average molecular weight of 0.1 to 10 million of the copolymer (A) from the viewpoint of uniform adsorption to pulp fibers, solubility in water or uniform dispersibility before the papermaking process. , 0.5 million-5 million are more preferable, and 10,000-2 million are especially preferable. Here, the weight average molecular weight of a copolymer (A) is measured by GPC on condition of the following. As the converted molecular weight, either of polyacrylamide or polyethylene glycol (standard sample for GPC) of the reagent can be used, and any of the above-mentioned ranges may be satisfied. Preferably polyethylene glycol is used. From a volume viewpoint, 10,000-300,000 are preferable in polyacrylamide conversion, and 0.50,000-150,000 are preferable in polyethyleneglycol conversion. From the viewpoint of the paper power, 40,000 to 100,000 in terms of polyacrylamide and 20,000 to 500,000 in terms of polyethylene glycol are preferable.

[Measuring conditions]

Column: α-M × 2 (TOSO)

Eluent: 50 mM LiBr, 1% acetic acid / ethanol = 70/30 (volume ratio)

Flow rate: 1 ml / min

Column temperature: 40 ℃

Detector: RI                 

Sample concentration: 4mg / ml

Injection volume: 100 μl.

The polymerization method of the copolymer (A) in this invention is not specifically limited, For example, well-known polymerization methods, such as solution polymerization and block polymerization using a polymerization initiator, can be employ | adopted. The polymerization method can be carried out either batchwise or continuously, and any known solvent can be used as the solvent used if necessary, and is not particularly limited. As such a solvent, it is water, for example; Alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol; Aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, cyclohexane and n-heptane; Esters such as ethyl acetate; Although ketones, such as acetone and methyl ethyl ketone, etc. are mentioned, 1 type, or 2 or more types chosen from the group which consists of water and C1-C4 lower alcohol from a viewpoint of the solubility of a monomer mixture and the obtained copolymer (A) are mentioned. It is preferable to use.

As a polymerization initiator, a well-known thing can be used and it is not specifically limited. As such a polymerization initiator, For example, persulfates, such as ammonium persulfate, sodium persulfate, potassium persulfate; Hydrogen peroxide; Azo compounds such as azobis-2methylpropionamidine hydrochloride and azoisobutyronitrile; Peroxides, such as a benzoyl peroxide, lauroyl peroxide, and cumene hydroperoxide, etc. are mentioned, These 1 type, or 2 or more types can be used. At this time, as an accelerator, reducing agents such as sodium hydrogen sulfite, sodium sulfite, molar salts, sodium pyro sulfite, sodium formaldehyde sulfoxylate and ascorbic acid; You may use together 1 type (s) or 2 or more types, such as amine compounds, such as ethylenediamine, sodium ethylenediamine tetraacetate, and glycine.

Chain transfer agents can also be used as needed. As a chain transfer agent, a well-known thing can be used and it does not specifically limit, For example, mercaptoethanol, mercaptoglycerol, mercaptosuccinic acid, mercaptopropionic acid, mercaptopropionic acid 2-ethylhexyl ester, and octanoic acid 2-mercaptoethyl ester , 1,8-dimercapto-3,6-dioxaoctane, decanthriol, dodecyl mercaptan, hexadecanethiol, decanthiol, carbon tetrachloride, carbon tetrabromide, α-methylstyrene dimer, terpinone, α -Terpinene, (gamma) -terpinene, dipentene, 2-aminopropan-1-ol, etc. can be mentioned, These 1 type, or 2 or more types can be used.

Although polymerization temperature is suitably determined by the polymerization method, solvent, polymerization initiator, and chain transfer agent used, it is normally performed within the range of 0-150 degreeC.

The solvent may be extracted from the reactant obtained after polymerization by drying under reduced pressure, and the polymer may be separated and operated by an operation such as pulverization.

In the present invention, the surfactant (B) is a surfactant other than the copolymer (A) and the water-soluble polymer (C) described later, and the surfactant (B) is a structural unit having a dissolution parameter of the copolymer (A) of 20.5 or less. Although what kind of thing may be used as long as it forms hydrophobic interaction, the structure which has a C2 or more, preferably 3-40, more preferably 4-24 alkyl group is preferable, and molecular weight or distribution like polyoxyalkylene glycol is preferable. The number average molecular weights of 50-10000 and the range of 100-5000 are preferable as long as it has.

Examples of the surfactant (B) include anionic, cationic, nonionic and amphoteric surfactants, and preferably have a structure that does not interact with an ionic group which is a structural unit of the copolymer (A), and more preferably nonionic. .

The surfactant (B) preferably has a critical micelle concentration or solubility in the aqueous phase (25 ° C.) of 5000 mg / g or less, more preferably 1000 mg / g or less.

As HLB, surfactant (B) has the preferable range of -5-15, and the range of 2.1-12 is still more preferable. HLB in this invention is defined by the following formula.

HLB = Σ hydrophilic group number + Σ lipophilic group number + 7

The lipophilic and hydrophilic values in the present invention are set forth in Tenside Surfactant Deterg VOL. 29 No. The HLB _{M base values in} Tables 2 and 3 described in 2, pages 109-113 (1992) are used. Chinyugi is the HLB _M gigap of Table 2, the hydrophilic group is used for HLB _M gigap in Table 3. _{^{However, -OPO (O -) 2,}} (-O) 2 POO -, (-O) ₃ PO, if the phosphoric acid ester is used as the hydrophilic group +12.3 value.

Among the surfactants (B), for example, anionic surfactants include alkyl sulfates, polyoxyalkylene alkyl ether sulfates, fatty acids and salts thereof. Examples of cationic surfactants include alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, benzalkonium chloride and alkyl amine salts. Examples of nonionic surfactants include fatty acid esters of polyhydric alcohols, alkylene oxide adducts of fatty acid esters of polyhydric alcohols, fatty acid amides, alkylene oxide adducts of fatty acid amides, alkylene oxide adducts of alkylamines, and alcohols. And / or an alkylene oxide adduct of the alcohol, a polyalkylene glycol having a C 2 to C 4 oxyalkylene group as a structural unit, preferably a polyalkylene having an C 3 to 4 oxyalkylene group in the structural unit Glycol etc. are mentioned. Examples of the amphoteric surfactant include alkyl trimethylamino acetate betaine, alkyl dimethylamine oxide, alkyl carboxymethyl hydroxyethyl imidazolium betaine, alkyl amide propyl betaine, alkyl hydroxy sulfobetaine and the like. Alkylene oxide adducts of alcohols having 2 to 40 carbon atoms, preferably 4 to 24 carbon atoms, having an alkylene oxide adduct having 2 to 4 carbon atoms having an alkylene oxide group of more than 0 and less than 150 mol on average per mole of the alcohol. The alkylene oxide adduct which has a C2-C4 alkylene oxide group of more than 0 mol and less than 50 mol on average per 1 mol of this alcohol is more preferable. Moreover, it is preferable from a viewpoint of paper strength improvement that surfactant (B) is water-soluble. In this invention, that surfactant (B) is water-soluble means that 1 weight% aqueous solution of surfactant (B) at 25 degreeC is transparent.

In the present invention, that the surfactant (B) is water-soluble means that a 1% by weight aqueous solution of the surfactant (B) at 25 ° C is transparent, and that the transparent is measured by a cell of 10 mm of optical path at 660 nm of visible light of the aqueous solution. By transmittance | permeability (%), it means that it is 90% or more when water is made into 100%. Moreover, surfactant (B) which is not soluble in water or not water-soluble at room temperature is added to water at 1 weight%, and it stir-mixes at 80 degreeC for 30 minutes, After that, it is cooled to room temperature (25 degreeC), maintaining stirring. Then check the aqueous solution.

In the papermaking improving agent for papermaking of the present invention, the weight ratio of the copolymer (A) and the surfactant (B) is (A) / (B) = 99/1 to 1/99, preferably 95/5 to 5 / 95 More preferably, it is 85 / 15-15 / 85. It is preferable that the mixture of copolymer (A) and surfactant (B) is water-soluble.

The papermaking paper improver for the present invention also has a weight average molecular weight of 10 to 10 million, preferably 10,000 to 10 million or a viscosity of 1% aqueous solution at 25 ° C of 1 to 4000 mPa · s, preferably 2 to 2000 mPa S, More preferably, it can contain the water-soluble polymer (C) which satisfy | fills at least any one of 3-1000 mPa * s. If it is the weight average molecular weight or viscosity of this range, it will be excellent in the paper force improvement effect. In addition, the weight average molecular weight of water-soluble polymer (C) and the viscosity of 1% aqueous solution are measured by the following method.

<Measurement method of weight average molecular weight>

The weight average molecular weight of the water-soluble polymer (C) was measured by GPC under the following conditions. Pullulan was used for the converted molecular weight.

[Measuring conditions]

Column: α-M × 2 (TOSO)

Eluent: 0.15M Na ₂ SO ₄ /1% acetic acid

Flow rate: 1 ml / min

Column temperature: 40 ℃

Detector: RI                 

Sample concentration: 2mg / ml

Injection volume: 100 μl.

<Measuring method of viscosity>

A 1 wt% aqueous solution of the water-soluble polymer (C) was prepared and measured under a condition of 25 ° C. using a B-type viscometer (manufactured by Tokyo Instruments). The number of revolutions is 60 r / min, and depending on the viscosity, No. 1 rotor is 80 mPa · s or less, No. 2 rotor is more than 80 mPa · s and 400 mPa · s or less, No. 3 rotor is more than 400 mPa · s and 1600 mPa · s, 1600 mPa. No. 4 and a rotor greater than 8000 mPa · s were used.

The water-soluble polymer (C) does not correspond to the copolymer (A) and the surfactant (B), and polyvinyl alcohol polymer, polyacrylamide polymer, polyethyleneimine, urea formaldehyde resin, melamine formaldehyde resin, epoxidation Polyamide resin, carboxymethyl cellulose, starch and modified starch, vegetable gum and the like, but in particular, polyacrylamide-based polymer, polyvinyl alcohol-based polymer, starch and modified starch, and one selected from the group consisting of vegetable gums. The above compound is preferable.

Starches include, for example, natural starches such as corn starch, potato starch, wheat starch and tapioca starch. In addition, modified starch refers to the processed starch which physically and / or chemically processed the starch as described on pages 36-37 of "The Dictionary of Paper and Processed Chemicals" (Tech Times, 1991). Oxidized starch treated with an oxidizing agent such as sodium hypochlorite or periodate, for example, 3-chloro-2-hydroxypropyltrimethylammonium chloride, glycidyltrimethylammonium chloride or diethylaminoethyl chloride hydrochloride Preference is given to cationic starches in which cationic groups are introduced into the molecule. In addition, as shown on page 283 of "Drug and Processing Chemical Dictionary", modified starch in which a phosphate group is further introduced into the cationic starch may be referred to as positive starch. In the present invention, this is also included in the cationic starch. Shall be. When cationic starch is used especially, even if the addition amount increases, it is more preferable because paper force improvement can be achieved without damaging a volume improvement effect. Moreover, 0.005-0.1 are preferable and, as for the substitution degree of the cation of cationized starch, 0.01-0.08 are more preferable. Moreover, the substitution degree of the cation of a cationic starch is the average value of the number of the hydroxyl groups in which the cation group was introduce | transduced among all the hydroxyl groups which one glucose residue which comprises a cationized starch has, and becomes 3 when it introduces into all hydroxyl groups.

When the water-soluble polymer (C) is contained in the present invention, the weight ratio of the copolymer (A), the surfactant (B), and the water-soluble polymer (C) in the papermaking agent for papermaking of the present invention is preferably [copolymer (A). ) + Surfactant (B)] / water-soluble polymer (C) is 99/1 to 10/90, more preferably 98/2 to 20/80.

The papermaking improving agent for papermaking of the present invention may be added to a papermaking process in a state where a copolymer (A) and a surfactant (B) or a copolymer (A), a surfactant (B) and a water-soluble polymer (C) are respectively mixed, You may add to a papermaking process separately, respectively. It is preferable to add especially in the state which mixed the copolymer (A) and surfactant (B).

The papermaking improving agent for papermaking of the present invention is added at any one of the papermaking processes, and may be added as it is, or may be added after dilution with water or the like as necessary.                 

The paper-based paper improving agent of the present invention can be widely applied to mechanical pulp such as thermo-based pulp (TMP), virgin pulp such as chemical pulp such as LBKP, and pulp raw material such as used paper pulp. When mix | blending a waste paper pulp, the compounding quantity is 10 weight% or more in raw material pulp is preferable, and 30 weight% or more is more preferable.

The papermaking paper improver of the present invention is added at any one step before the papermaking process (internal). As the place of addition, prior to the papermaking process in which the water is filtered to form a paper layer while the lean liquid of the pulp raw material proceeds on the wire mesh, the dissociation or beating machine such as a pulper or refiner, a machine chest, a head box or a white water tank, etc. Although it may add in a tank or piping connected with these facilities, the place which can be mix | blended uniformly with a pulp raw material, such as adding with a refiner, a machine chest, a head box, is preferable. It is preferable that the paper paper improving agent for papermaking of this invention is added to the pulp raw material, and then it is paper-made as it is and remains mostly in a pulp sheet.

The papermaking speed of the pulp sheet produced by adding the papermaking improving agent for papermaking of the present invention is preferably 200 m / min or more, more preferably 300 m / min or more, and 500 m / min from the viewpoint of the remarkable effect of improving the volume, whiteness and opacity. Minutes or more are particularly preferred.

At the time of papermaking, a size agent, a filler, a yield improver, a filtrate improver, a paper force improver, or the like may be added. In particular, in order for the papermaking improving agent for papermaking of the present invention to express its function, it is important to fix it in pulp, and therefore, it is preferable to add an accelerator which promotes fixing. Examples of accelerators for promoting fixation include aluminum sulfate, compounds having acrylamide groups, and polyethyleneimines. As for the addition amount of the promoter which promotes fixation, 0.01-5 weight part is preferable with respect to 100 weight part of pulp raw materials. In particular, when using the copolymer (A) which has an anionic structural unit, the use of the promoter which accelerates | stimulates fixing can be anticipated.

The paper-based paper improving agent of the present invention is preferably added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the pulp raw material, but at least one of optical properties such as volume improvement effect, whiteness or opacity, even with a small amount of 0.1 to 5 parts by weight is added. Is improved.

The compound which becomes the papermaking paper improving agent of the present invention can be used as a paper volume improving agent, papermaking whiteness improving agent, papermaking opacity improving agent.

The pulp sheet obtained by using the papermaking agent for papermaking according to the present invention has a density of 0.02 g / cm 3 or more, preferably 0.03 g / cm 3 or less, which is an index of volume improvement, compared to the non-added sheet, and the whiteness is 0.5 point or more. It is preferable that it is 0.6 point or more high preferably, and opacity is 1.0 point or more, It is preferable that it is 1.2 point or more preferably. In addition, it is preferable to satisfy two or more of the above effects, and particularly to satisfy three.

The paper improver according to the present invention can improve the burst strength while improving any one or more of volume, whiteness and opacity. In addition, the burst strength correlates with other paper force performances such as tensile strength, tear strength, and interlaminar strength, and the evaluation of the burst strength is an index of these. In the present invention, in view of the paper force required in operation, product processing, and product use, the aforementioned standard non-rupture strength improvement index is preferably -3000 or more, more preferably -1500 or more, and -500 or more It is preferable and 0 or more are especially preferable.

In addition, the pulp sheet obtained by using the papermaking improving agent for papermaking according to the present invention is a newspaper winding paper, a printing paper, and an information sheet in the item classification described on pages 455 to 460 of the Paper Pulp Technology Manual (published by the Paper Pulp Technology Association, 1992). , Paper, such as packaging paper, or cardboard is preferably used.

According to the present invention, a paper-based paper improving agent capable of achieving at least one of the desired volume improvement, whiteness improvement or opacity improvement, etc., in the weight reduction of paper and multiplication of high-fat pulp even with a small amount of addition, Is provided. In addition, according to the papermaking improving agent for papermaking according to the present invention, a pulp sheet with improved volume, whiteness and opacity, and furthermore, paper strength can be obtained.

Hereinafter, unless otherwise indicated, "part" is a weight part and "%" is a weight%.

<Production Example of Copolymer (A)>

(I) copolymer No. A-1 Production Example

592.3 parts by weight of ethanol, 14.5 parts by weight of water, 58.0 parts by weight of methyl chloride quaternary (QDM) dimethylaminoethyl methacrylate in a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser; and 240 parts by weight of methoxypolyalkylene glycol methacrylate (ethylene oxide / propylene oxide = 5/10 mol, random adduct) (MEPAGMA) was added and nitrogen-substituted. Subsequently, after heating up to 67 degreeC under nitrogen atmosphere, 84.8 weight part of 2% -2,2'- azobis (2, 4- dimethylvaleronitrile) (V-65) ethanol solutions were dripped over 90 minutes. Next, the mixture was aged at the same temperature for 1 hour, and then 10.4 parts by weight of a 4% -2,2'-azobis (2,4-dimethylvaleronitrile) ethanol solution was added dropwise over 30 minutes, followed by 2 hours at the same temperature. After aging, the mixture was cooled to obtain a copolymer No. 140000 of a weight average molecular weight (polyacrylamide equivalent). A-1 solution was obtained.

Copolymer No. A-2 is copolymer No. It manufactured according to the polymerization method of A-1 manufacture example.

(II) Copolymer No. Preparation Example of A-3

203.9 parts by weight of ethanol and 167.6 parts by weight of water were added to a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser to replace nitrogen. Subsequently, after heating up to 67 degreeC under nitrogen atmosphere, 72.9 weight part of aqueous methyl chloride quaternary compounds (DMAPAA-Q) of 75% -dimethylaminopropyl acrylamide, and 72.8 weight part of tertiary octyl acrylamide (t-OAAm) 73.2 parts by weight of a solution of 24.1-2,2'-azobis (2-amidinopropane) dihydrochloride (V-50), a mixture of 144.1 parts by weight of acrylamide (AAm), 161.1 parts by weight of ethanol, and 107.4 parts by weight of water. Two parts of liquid were dripped simultaneously, and both liquids were dripped over 90 minutes. Next, after aging at the same temperature for 3 hours, the mixture was cooled to obtain a copolymer No. 30000 of a weight average molecular weight (polyacrylamide equivalent) 30000. A-3 solution was obtained.

(III) Copolymer No. Preparation Example of A-4

In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 375 parts by weight of ethanol, 310.4 parts by weight, 67.8 parts by weight of a 75% DMAPAA-Q aqueous solution, 6 parts by weight of t-0AAm, AAm 131.2 The weight part was added and nitrogen-substituted. Then, after heating up to 62 degreeC in nitrogen atmosphere, 48 weight part of 0.7% V-50 aqueous solution was dripped over 90 minutes at the same temperature. Next, after aging at the same temperature for 6 hours, the mixture was cooled to give a copolymer No. of 180000 with a weight average molecular weight (polyacrylamide equivalent). A-4 solution was obtained.

Copolymer No. A-5-A-10 is copolymer No. It prepared according to the polymerization method of Preparation Example A-4.

In Table 1, the copolymer (A), its monomer composition, and the weight average molecular weight were shown. In Table 2, surfactant (B) was shown. Table 3 shows the viscosity of the water-soluble polymer (C) and its weight average molecular weight or 1% aqueous solution. Table 4 also shows the standard volumetric improvement, standard whiteness improvement, standard opacity improvement, and standard non-rupture strength improvement index of the paper quality improver using these as the addition amount of Table 4 (vs. by weight per 100 parts by weight of pulp).

<Paper quality improver>

The aqueous solution of the copolymer (A) of Table 1, surfactant (B) of Table 2, and 1 weight% of active ingredients of the water-soluble polymer of Table 3 was prepared, respectively, and it used so that it might become predetermined ratio. In addition, when the surfactant (B) is not water-soluble and when the 1% by weight aqueous solution of the mixture of the copolymer (A) and the surfactant (B) is not water-soluble, the surfactant ( B) was added, water was added so that solid content concentration of surfactant (B) might be 1 weight%, and it stirred and mixed at 80 degreeC for 30 minutes, After that, it was left to stand to room temperature and used as a dispersion liquid, stirring.

Monomer Composition of Copolymer Weight average molecular weight Monomer (I) Monomer (II) Monomer (III) Monomer (IV) (I) / (II) / (III) weight ratio Monomer (IV) ratio (mol%) Polyacrylamide conversion Polyethylene glycol conversion Copolymer number A-1 MEPAGMA QDM - - 80/20/0 - 140000 60000 A-2 2EHA MOEDES DMAAm - 24/16/60 - 140000 65000 A-3 t-OAAm DMAPAA-Q AAm - 27/20/53 - 30000 15000 A-4 t-OAAm DMAPAA-Q AAm - 27/20/53 - 180000 90000 A-5 t-OAAm DMAPAA-Q AAm - 10/23/67 - 250000 125000 A-6 t-OAAm DMAPAA-Q AAm - 19/22/59 - 240000 120000 A-7 t-OAAm DMAPAA-Q AAm - 34/17/47 - 150000 75000 A-8 t-OAAm DMAPAA-Q AAm MBAAm 27/20/53 0.2 1090000 470000 A-9 t-OAAm DMAPAA-Q AAm TAC 27/20/53 0.1 290000 140000 A-10 BMA MOEDES AAm - 20.2 / 29.4 / 50.4 - - 25000 Monomer (I): Nonionic unsaturated monomer having a dissolution parameter of 20.5 (MPa) ^1/2 or less
Monomer (II): Anionic or Cationic Monomer
Monomer (III): Nonionic unsaturated monomer with dissolution parameter of at least 26.6 (MPa) ^1/2 (excluding DMAAm)
Monomer (IV): Crosslinkable Monomer
MEPAGMA: methoxypolyalkylene glycol methacrylate (dissolution parameters: 17.6, ethylene oxide / propylene oxide = 5/10 mol, random adduct)
2EHA: 2-ethylhexyl acrylate (dissolution parameter: 16.0)
T-OAAm: tertiary octylacrylamide (dissolution parameter: 16.6)
BMA: n-butyl methacrylate (dissolution parameter: 16.8)
QDM: methyl chloride quaternized with dimethylaminoethyl methacrylate
MOEDES: Diethyl sulfuric acid quaternized with dimethylaminoethyl methacrylate
DMAPAA-Q: methyl chloride quaternized with dimethylaminopropylacrylamide
DMAAm: Dimethylacrylamide (dissolution parameter: 21.7)
AAm: acrylamide (dissolution parameter: 30.1)
MBAAm: methylenebisacrylamide
ㆍ TAC: isocyanuric acid triallyl

number Compound name HLB receptivity Transmittance% B-1 EO _2.5 PO _1.5 EO ₃ (block) adduct of lauryl alcohol (lauryl alcohol: lauryl alcohol / myristyl alcohol = 7/3 weight ratio) 3.7

99 B-2 EO ₂₃ adduct of lauryl alcohol 10.4

100 B-3 Diethylene glycol monobutyl ether 6.7

100 B-4 PO ₅ Adduct of Lauryl Alcohol 1.6 × 3 B-5 EO ₆ adduct of stearyl alcohol 1.5 × One B-6 Stearic Acid Monoglycerides 2.0 × 0 B-7 Pentaerythritol stearic acid ester
(45 equivalent% of ester average substitution degree) －3.3 × 0 B-8 Stearyltrimethylammonium Chloride 5.2

100 B-9 Lauric acid propyl betaine 5.4

100 B-10 Sodium Lauryl Sulfate 13.2

99 In the table, EO is ethylene oxide, PO is propylene oxide, and numbers are average added moles.
In addition, water-soluble "

Means water-soluble and "x" means not water-soluble.

number Water soluble polymer C-1 Amphoteric polyacrylamide
(Harima Kasei, Hamid EX113, weight average molecular weight 2 million) C-2 Cationic starch
[Nippon NSC, cato 308, 1% aqueous solution viscosity 151 mPa.s (25 degreeC)]

Paper Enhancer Number Furtherance Properties Copolymer
(A) Surfactants
(B) Water soluble polymer
(C) Standard
volume
Improvement
(g / cm3) Standard
Whiteness
Improvement
(point) Standard
Opacity Improvement
(point) Standard Non-Rupture Strength Improvement Index
(%) Kinds Addition amount
(Parts by weight) Kinds Addition amount
(Parts by weight) Kinds Addition amount
(Parts by weight) Invention One A-1 1.0 B-1 1.0 - - 0.0530 0.0 2.6 －897 2 A-2 1.0 B-1 1.0 - - 0.0530 0.4 1.4 -600 3 A-3 1.0 B-1 1.0 - - 0.0730 0.9 2.5 457 4 A-4 1.0 B-1 1.0 - - 0.0770 0.7 2.7 438 5 A-5 1.0 B-1 1.0 - - 0.0450 0.4 1.4 370 6 A-6 1.0 B-1 1.0 - - 0.0560 0.6 2.5 -380 7 A-7 1.0 B-1 1.0 - - 0.0590 0.5 2.7 -502 8 A-8 1.0 B-1 1.0 - - 0.0610 0.9 2.4 －394 9 A-9 1.0 B-1 1.0 - - 0.0600 0.8 2.2 345 10 A-4 1.0 B-1 1.0 C-1 1.0 0.0450 0.9 3.1 57 11 A-4 1.0 B-1 1.0 C-2 1.0 0.0480 1.0 3.0 53 12 A-3 1.0 B-2 1.0 - - 0.0420 0.6 1.9 -417 13 A-3 1.0 B-3 1.0 - - 0.0260 0.5 0.7 235 14 A-3 1.0 B-4 1.0 - - 0.0770 1.2 3.2 730 15 A-3 1.0 B-5 1.0 - - 0.0690 1.0 2.8 647 16 A-3 1.0 B-6 1.0 - - 0.0670 1.2 3.4 701 17 A-3 1.0 B-7 1.0 - - 0.0630 1.2 3.6 768 18 A-3 1.0 B-8 1.0 - - 0.0420 0.4 1.9 224 19 A-3 1.0 B-9 1.0 - - 0.0250 0.5 0.8 331 20 A-3 1.0 B-10 1.0 - - 0.0210 0.4 -0.3 -406 21 A-10 1.0 B-1 1.0 - - 0.0750 0.8 2.5 -434 Comparative product One A-4 2.0 - - - - 0.0140 0.1 0.6 284 2 - - B-1 2.0 - - 0.0120 0.5 －0.4 －433 3 - - - - C-1 1.0 -0.0170 -0.5 -0.3 Indefinite 4 - - - - C-2 1.0 -0.0100 －0.4 0.1 Indefinite 5 - - B-1 2.0 C-1 1.0 －0.004 -0.2 －1.5 Indefinite 6 Blank (no paper enhancer) - - - Indefinite

Example 1

[Pulp raw material]

The pulp raw material and virgin pulp shown below were used as a pulp raw material.

<Highland pulp>

The pulp is a hot water at 60 ° C and 1 part of sodium hydroxide, 3 parts of sodium silicate, 3 parts of 30% hydrogen peroxide, and a degreaser with respect to 100 parts of commercially available raw material notices (newspaper / billage = 70/30%). 0.3 part of DI-767 (Kao made) was added, and 0.4% of the deinking pulp slurry obtained by carrying out the floatation treatment, the water washing, and the concentration adjustment after understanding was used. Its Canadian standard filtered water rate (JIS P 8121) was 200 ml.

<Virgin Pulp>

The chemical pulp LBKP (softwood bleached kraft pulp) was understood and beaten at 25 ° C. as a beaker and used as a 0.4% LBKP slurry. Its Canadian standard filtrate (JISP 8121) was 410 ml.

[Papermaking method -1]

The paper pulp slurry was weighed so that the pulp basis weight of the sheet after papermaking became 55 g / m 2, and the pH was adjusted to 6.5 with aluminum sulfate. Subsequently, various paper quality improving agents for papermaking shown in Table 5 were added to the pulp, and then papermaking was carried out under the same conditions as in ① of the measuring method of the standard volumetric improvement to obtain a sheet. The addition amount in Table 5 is the weight percentage of the pulp. The density, whiteness, opacity, and specific burst strength of the obtained sheet were measured by the following method. The results are shown in Table 5.                 

[Papermaking method-2]

LBKP is weighed so that the pulp basis weight of the sheet after papermaking will be 84 g / m 2. Subsequently, various paper quality improving agents for papermaking shown in Table 6 were added to the pulp, and thereafter, papermaking was carried out under the same conditions as in ① of the measuring method of the standard volumetric improvement to obtain a sheet. The addition amount in Table 6 is the weight percentage of the pulp. Hereinafter, it evaluated similarly to the papermaking method-1. The results are shown in Table 6.

<Evaluation items and methods>

ㆍ density

The basis weight (g / m 2) and thickness (mm) of the humidified sheet were measured, and the density (g / cm 3) was obtained by the following formula.

Density = (Balance) / (Thickness) × 0.001

The smaller the density, the larger the volume, and the difference of 0.02 of the density is sufficiently recognized as a significant difference.

ㆍ Whiteness

Follows JIS P 8123 Hunter whiteness. The difference of 0.5 points in whiteness is sufficiently recognized as a significant difference.

Opacity

According to JIS P 8138A method. The 0.5 point difference in opacity is sufficiently recognized as a significant difference.

Burst Strength Paper Force                 

The burst strength was measured by JIS P 8112 method as a measurement item, the value was divided by basis weight, and the specific burst strength was calculated | required.

Furtherance Highland pulp Copolymer
(A) Surfactants
(B) Water soluble polymer
(C) density
(g / cm3) Whiteness
(%) Opacity (%) Non-rupture strength
[㎪ / (g / ㎡)] Kinds Addition amount
(%) Kinds Addition amount
(%) Kinds Addition amount
(%) Invention 1-1 A-1 1.0 B-1 1.0 - - 0.382 57.5 92.6 1.17 1-2 A-2 1.0 B-1 1.0 - - 0.384 57.6 92.1 1.43 1-3 A-3 1.0 B-1 1.0 - - 0.367 58.3 93.1 1.49 1-4 A-4 1.0 B-1 1.0 - - 0.361 58.1 93.7 1.66 1-5 A-5 1.0 B-1 1.0 - - 0.387 57.7 92.2 1.86 1-6 A-6 1.0 B-1 1.0 - - 0.377 57.9 92.7 1.76 1-7 A-7 1.0 B-1 1.0 - - 0.370 58.0 92.8 1.57 1-8 A-8 1.0 B-1 1.0 - - 0.378 58.2 93.0 1.88 1-9 A-9 1.0 B-1 1.0 - - 0.374 58.1 93.0 1.77 1-10 A-4 1.0 B-1 1.0 C-1 1.0 0.379 58.3 93.4 2.36 1-11 A-4 1.0 B-1 1.0 C-2 1.0 0.386 58.3 92.8 2.40 1-12 A-3 1.0 B-2 1.0 - - 0.387 57.9 92.9 1.85 1-13 A-3 1.0 B-3 1.0 - - 0.399 57.6 92.1 2.10 1-14 A-3 1.0 B-4 1.0 - - 0.362 58.4 93.9 0.98 1-15 A-3 1.0 B-5 1.0 - - 0.368 58.2 93.6 1.24 1-16 A-3 1.0 B-6 1.0 - - 0.369 58.4 93.6 1.18 1-17 A-3 1.0 B-7 1.0 - - 0.372 58.4 93.9 1.16 1-18 A-3 1.0 B-8 1.0 - - 0.387 57.7 92.7 2.03 1-19 A-3 1.0 B-9 1.0 - - 0.400 57.8 92.1 2.05 1-20 A-3 1.0 B-10 1.0 - - 0.405 57.7 91.4 2.08 1-21 A-10 1.0 B-1 1.0 - 0 0.363 58.2 93.6 1.71 Comparative product 1-1 A-4 1.0 - - - - 0.410 57.7 92.0 2.24 1-2 - - B-1 1.0 - - 0.414 57.7 91.3 2.14 1-3 - - - - C-1 1.0 0.430 56.8 90.5 3.18 1-4 - - - - C-2 1.0 0.426 56.9 91.3 2.99 1-5 - - B-1 1.0 C-1 1.0 0.424 57.2 90.8 3.08 1-6 Blank (no paper enhancer) 0.418 57.4 91.6 2.24

Furtherance LBKP Copolymer
(A) Surfactants
(B) Water soluble polymer
(C) density
(g / cm3) Whiteness
(%) Opacity
(%) Non-rupture strength
[㎪ / (g / ㎡)] Kinds Addition amount
(%) Kinds Addition amount
(%) Kinds Addition amount
(%) Invention 2-1 A-4 1.0 B-1 0.3 - - 0.535 81.7 88.0 2.80 2-2 A-4 1.0 B-1 0.5 - - 0.527 82.2 88.0 2.64 2-3 A-4 1.0 B-1 1.0 - - 0.511 82.4 89.0 2.22 2-4 A-4 0.3 B-1 1.0 - - 0.527 82.4 87.6 2.40 2-5 A-4 0.5 B-1 1.0 - - 0.521 82.4 87.8 2.40 2-6 A-4 0.3 B-1 0.3 - - 0.545 82.0 86.7 2.82 2-7 A-4 0.5 B-1 0.5 - - 0.534 82.0 87.5 2.71 2-8 A-4 1.0 B-1 1.0 C-1 1.0 0.543 82.6 89.4 3.43 2-9 A-10 1.0 B-1 1.0 - 0.0 0.513 82.5 88.8 2.26 Comparative product 2-1 A-4 3.0 - - - - 0.578 82.1 86.9 3.48 2-2 - - B-1 3.0 - - 0.570 82.0 85.1 3.01 2-3 - - - - C-1 1.0 0.605 81.2 86.0 4.81 2-4 - - B-1 1.0 C-1 1.0 0.592 81.5 84.8 4.61 2-5 Blank (no paper enhancer) 0.588 81.7 86.3 3.35

Tables 5 and 6 show that according to the papermaking improving agent for papermaking according to the present invention, in any of the paper pulp and virgin pulp (LBKP), a pulp sheet having improved volume, whiteness and opacity, and further improving paper strength is obtained. Can be.

Neither volume, whiteness, or opacity of the copolymer (A) alone of Comparative Example 1-1 of Table 5 nor the surfactant (B) alone addition of Comparative Product 1-2 were significantly improved. In addition, by adding water-soluble polymers (C) alone of Comparative Products 1-3 and 1-4, the paper force is improved compared to the blank, but the volume, whiteness, and opacity are lower than the blank. In addition, in combination of surfactant (B) and water-soluble polymer (C) of Comparative product 1-5, similar to Comparative products 1-3 and 1-4, paper force is improved compared to blank, but the volume, whiteness, The opacity is lower than the blank.

Even if the addition amount is increased by the addition of the copolymer (A) alone of the comparative product 2-1 of Table 6 or the surfactant (B) of the comparative product 2-2, neither of the volume, the whiteness nor the opacity is greatly improved. . In addition, by adding the water-soluble polymer (C) alone of Comparative Product 2-3, the paper force is improved compared to the blank, but the volume, whiteness, and opacity are lower than the blank. In addition, although paper strength improves compared with a blank by using surfactant (B) and water-soluble polymer (C) of the comparative product 2-4, neither volume, whiteness, nor opacity improves.

Claims (14)

delete The structural unit derived from at least one of the nonionic unsaturated monomer having a dissolution parameter of 20.5 (MPa) ^1/2 or less, the structural unit derived from at least one of the anionic or cationic monomer, and the dissolution parameter of 26.6 (MPa) ^{1 / The} copolymer (A) which has a structural unit derived from 1 or more types of nonionic unsaturated monomer which is ^two or more, and surfactant (B) is the range of (A) / (B) = 85 / 15-15 / 85 (weight ratio) As a paper-quality improvement agent for papermaking which contains and contains a paper-quality improvement effect of one or more of the following (i), (ii), and (iii): (i) a standard volume improvement of at least 0.02 g / cm 3; (ii) a standard opacity improvement of at least 1.0 point; (iii) a standard whiteness improvement of at least 0.5 point, The ratio of the constituent monomers of the copolymer (A) is 5 to 84% by weight of the nonionic unsaturated monomer having a dissolution parameter of 20.5 (MPa) ^1/2 or less, and 1 to 80% by weight in total of the anionic monomer and the cationic monomer. Paper-making paper improvement agent which is 15-94 weight% of nonionic unsaturated monomers whose parameter is 26.6 (MPa) ^1/2 or more. delete delete delete The papermaking improver for papermaking according to claim 2, wherein the constituent monomer of the copolymer (A) has a crosslinkable constituent monomer. The paper-quality improvement agent for papermaking of Claim 2 whose HLB of surfactant (B) exists in the range of -5-15. The papermaking agent for papermaking according to claim 2, wherein the surfactant (B) is nonionic. 3. The papermaking improver for papermaking according to claim 2, wherein the surfactant (B) is selected from an alkylene oxide adduct having an alcohol and an alkylene oxide group having 2 to 4 carbon atoms of more than 0 mol and less than 150 mol on average per mole of the alcohol. . The paper-quality improving agent for papermaking of Claim 2 in which surfactant (B) is water-soluble. The water-soluble polymer (C) according to claim 2, further comprising at least any one of a weight average molecular weight of 10 to 10 million or a viscosity of 1% aqueous solution at 25 ° C of 1 to 4000 mPa · s. Paper quality improver. The papermaking paper making agent according to claim 2, wherein the standard non-rupture strength improvement index produces an effect of -3000 or more. The manufacturing method of the pulp sheet which adds the paper-quality improvement agent for papermaking of Claim 2 in any of the steps before a papermaking process, and is made at the papermaking speed of 200 m / min or more. The pulp sheet containing the paper-quality improvement agent for papermaking of Claim 2.